The present invention relates to a display device that scans a color phosphor screen with a laser beam.
Display devices of this type can display video and other color images similar to those displayed by a conventional cathode-ray tube. The advantage of scanning a color phosphor screen with a laser beam is that a laser beam does not require a large, evacuated glass tube for propagation. Issues must be addressed, however, in these display devices relating to modulating the laser beam and separating of the different colors in the display.
U.S. Pat. No. 5,003,179 describes a display device in which the intensities of three infrared laser beams are independently modulated, the intensity of each beam being selectively blanked to illuminate only phosphors which produce light of the desired color. Such a display device has drawbacks, however, because the need for selectively blanking light beams intensities is inconvenient.
Japanese Patent Kokai Publication No. 323686/1992 describes a display device that modulates the intensity of a single laser beam, which illuminates red, green, and blue phosphors. This system requires that the beam be modulated at three times the normal rate, and is inconsistent with conventional video signal processing.
Japanese Patent Kokai Publication No. 323686/1992 discloses a display device that scans a phosphor screen with a single ultraviolet beam, which is generated by converting the wavelength an infrared laser beam. This system is similarly inconsistent with conventional video signal processing.